Abstract
Three different heat treatments, peak aging (T6), over-aging (T74) and retrogression and re-aging (RRA), were conducted for the A7N01 aluminum alloy respectively. The evolution of the corrosion behavior in the intergranular corrosion (IGC) solution of the three alloys was studied by electrochemical impedance spectroscopy (EIS) and morphology analysis. The results showed that corrosion pits were formed on the three alloys surfaces after 6 h immersion in IGC solution. The T6 alloy had obvious intergranular corrosion and the depths of corrosion pits decreased in the order T6 > RRA > T74. The EIS results showed that in the initial stage of the reaction, the Nyquist plot were composed by a high frequency capacitance loop and a low frequency inductive loop. After 6 h immersion the inductive loop still existed in T74 alloy, while it disappeared in the other two alloys and was replaced by a low frequency capacitance loop. In the initial stage of reaction, pitting corrosion sensitivity of T74 alloy was the smallest, RRA alloy was the second one, and T6 alloy was the highest one. The equivalent circuit results showed that when the immersion time was between 6 and 144 h, the polarization resistance (Rpit) increased gradually with the immersion time prolonging. The Rpit decreased in the order T6 > RRA > T74 alloy, which attribute to the formation of corrosion products on the new interface. In the later stage of the immersion (after 144 h), the Rpit of the three alloys decreased as a result of the abscission of the corrosion products on the alloy surface. After soaking for 168 h, the Rpit of T74 alloy reached the maximum value, RRA alloy was slightly higher than T6 alloy. In the late stage, the corrosion susceptibility to intergranular corrosion sensitivity decreased in the order T6 > RRA > T74.
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References
R. Ranganatha, V.A. Kumar, V.S. Nandi et al., Multi-stage heat treatment of aluminum alloy AA7049. Trans. Nonferrous Metals Soc. Chin. 23(6), 1570–1575 (2013)
T. Marlaud, B. Malki, C. Henon et al., Relationship between alloy composition, microstructure and exfoliation corrosion in Al–Zn–Mg–Cu alloys. Corros. Sci. 53(10), 3139–3149 (2011)
B. Sarkar, M. Marek, E.A. Starke, The effect of copper content and heat treatment on the stress corrosion characteristics of Ai-6Zn-2 Mg-X Cu alloys. Metall. Mater. Trans. A 12(11), 1939–1943 (1981)
B. Li, X. Wang, H. Chen et al., Influence of heat treatment on the strength and fracture toughness of 7N01 aluminum alloy. J. Alloy. Compd. 678, 160–166 (2016)
S. Chen, K. Chen, G. Peng et al., Effect of heat treatment on strength, exfoliation corrosion and electrochemical behavior of 7085 aluminum alloy. Mater. Des. 35, 93–98 (2012)
J. Wloka, T. Hack, S. Virtanen, Influence of temper and surface condition on the exfoliation behavior of high strength Al–Zn–Mg–Cu alloys. Corros. Sci. 49(3), 1437–1449 (2007)
P.A. Rometsch, Y. Zhang, S. Knight, Heat treatment of 7xxx series aluminium alloys—some recent developments. Trans. Nonferrous Metals Soc. Chin. 24(7), 2003–2017 (2014)
F. Cao, Z. Zhang, J. Li et al., Exfoliation corrosion of aluminum alloy AA7075 examined by electrochemical impedance spectroscopy. Mater. Corros. 55(1), 18–23 (2015)
Z. Cvijović, M. Rakin, M. Vratnica et al., Microstructural dependence of fracture toughness in high-strength 7000 forging alloys. Eng. Fract. Mech. 75(8), 2115–2129 (2008)
M. Keddam, C. Kuntz, H. Takenouti et al., Exfoliation corrosion of aluminium alloys examined by electrode impedance. Electrochim. Acta 42(1), 87–97 (1997)
C.N. Cao, J. Wang, H.C. Lin, Effect of Cl-ion on the impedance of passive-film-covered electrodes. J. Chin. Soc. Corros. Prot. 9(4), 261–270 (1989)
X.H. Wang, J.H. Wang, F.U. Cong-Wei, Characterization of pitting corrosion of 7A60 aluminum alloy by EN and EIS techniques. Trans. Nonferrous Metals Soc. Chin. 24(12), 3907–3916 (2014)
R. Jurczakowski, C. Hitz, A. Lasia, Impedance of porous Au based electrodes. J. Electroanal. Chem. 572(2), 355–366 (2004)
T. Pajkossy, Impedance spectroscopy at interfaces of metals and aqueous solutions—surface roughness, CPE and related issues. Solid State Ionics 176(25–28), 1997–2003 (2005)
M.A. Jingling, J.B. Wen, G.X. Li, X.V. ChunHua, The corrosion behaviour of Al−Zn−In−Mg−Ti alloy in NaCl solution. Corros. Sci. 52(2), 534–539 (2010)
Y. Deng, Z.M. Yin, K. Zhao, J.Q. Duan, J. Hu, Z.B. He, Effects of Sc and Zr microalloying additions and aging time at 120 °C on the corrosion behaviour of an Al–Zn–Mg alloy. Corros. Sci. 65, 288–298 (2012)
N. Birbilis, M.K. Cavanaugh, R.G. Buchheit, Corros. Sci. 48(12), 4202–4215 (2006)
C.Q. Ye, R.G. Hu, S.G. Dong et al., J. Electroanal. Chem. 688(4), 275–281 (2013)
X. Lou, P.M. Singh, Phase angle analysis for stress corrosion cracking of carbon steel in fuel-grade ethanol: experiments and simulation. Electrochim. Acta 56(4), 1835–1847 (2011)
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Hu, J., Huang, C., Wang, X. (2018). Corrosion Behavior Evolution of A7N01 Aluminum Alloys with Different Heat Treatments in the IGC Solution. In: Han, Y. (eds) Advances in Materials Processing. CMC 2017. Lecture Notes in Mechanical Engineering. Springer, Singapore. https://doi.org/10.1007/978-981-13-0107-0_53
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DOI: https://doi.org/10.1007/978-981-13-0107-0_53
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